Marlin (Louis C.K), a clown fish, is overly cautious with his son, Nemo (Azhy Robertson), who has a foreshortened fin. When Nemo swims too close to the surface to prove himself, he is caught by a diver, and horrified Marlin must set out to find him. A blue reef fish named Dory (Kristen Wiig) -- who has a really short memory -- joins Marlin and complicates the encounters with sharks, jellyfish, and a host of ocean dangers. Meanwhile, Nemo plots his escape from a dentist's fish tank.